Carbamazepine µg/mL → µmol/L
Convert carbamazepine from µg/mL to µmol/L
Sources last checked: 2026-11-03
Carbamazepine µg/mL → µmol/L
Convert carbamazepine from µg/mL to µmol/L
Converts units only; reference ranges depend on the laboratory, the assay and the patient.
What is the Carbamazepine µg/mL → µmol/L?
Carbamazepine levels are reported in µg/mL (identical to mg/L) by most laboratories in Germany, Austria, Turkey and the USA, and in µmol/L by some SI-reporting laboratories. This converter multiplies by 4.232, the factor that follows from the molar mass of carbamazepine (236.27 g/mol). It converts the parent drug only.
When to use it
- Comparing a carbamazepine level in µg/mL with a source written in µmol/L
- Documenting therapeutic drug monitoring for a patient moving between laboratories
- Pharmacokinetic exercises using SI units
- Exam questions on enzyme-inducing antiepileptic drugs
When not to use it
- Carbamazepine-10,11-epoxide, the active metabolite, which has a different molar mass and is reported separately when measured
- Oxcarbazepine or eslicarbazepine, which are monitored as their own metabolite, not as carbamazepine
- Interpreting a level drawn before steady state or without the time of the last dose
How it is calculated
Carbamazepine (µmol/L) = carbamazepine (µg/mL) × 4.232
Clinical pearls and limitations
- Converts units only; reference ranges depend on the laboratory, the assay and the patient.
- 1 µg/mL = 1 mg/L = 4.232 µmol/L; conversely 1 µmol/L = 0.2363 µg/mL.
- Carbamazepine induces its own metabolism: after starting or increasing the dose, clearance rises over several weeks, so an early level can overestimate later ones.
- The epoxide metabolite contributes to both effect and toxicity and can accumulate (e.g. with valproate co-medication) without a rise in the parent-drug level; immunoassays differ in how much epoxide they cross-detect.
- Carbamazepine is a strong inducer of other drugs, and inhibitors such as some macrolides or azoles can raise its level abruptly.
Frequently asked questions
How do I convert carbamazepine from µg/mL to µmol/L?
Multiply by 4.232. For example, 7.3 µg/mL × 4.232 = 31 µmol/L.
Why is the carbamazepine factor 4.232?
Carbamazepine has a molar mass of 236.27 g/mol. 1 µg/mL equals 1 mg/L, and 1000 ÷ 236.27 = 4.232 µmol/L.
Can I use this for carbamazepine epoxide?
No. The epoxide has a different molar mass, so this factor would give a wrong result.
Evidence and guidelines
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<p><a href="https://medelix.ai/en/calculators/carbamazepine-ug-ml-to-umol-l">Carbamazepine µg/mL → µmol/L calculator by Medelix</a></p>For healthcare professionals and medical students. These tools support, and do not replace, clinical judgement. Always check results against the original source and your local protocols.